Analysis of spatial and temporal distribution and seasonal potential sources of atmospheric PM2.5 in Chenzhou City

Abstract

Abstract In order to study the air pollution prevention and control situation in Chenzhou City, southern Hunan Province, the ambient air pollutant concentration data of Chenzhou City in southern Hunan Region from March 2022 to February 2023 was selected, and Kriging interpolation analysis was used to simulate the temporal and spatial changes of PM2.5 concentration in Chenzhou City. trend, and used the HYSPLIT air mass backward trajectory model to conduct cluster analysis to explore the transmission paths and potential source area distribution of PM2.5 pollution in Chenzhou City in different seasons. The results showed that the PM2.5 concentration in Chenzhou City showed obvious seasonal differences. The highest average concentration appears in winter (75.13 µg·m-3), followed by autumn and spring, and the lowest occurs in summer (27.64 µg·m-3). At the same time, PM2.5/PM10 is higher than 0.55 in autumn and winter. This shows that Chenzhou City is dominated by fine particulate matter pollution in autumn and winter. The spatial distribution of the annual mean value of PM2.5 pollution shows the characteristics of "from north to south in the west and central part, and low in the east". PM2.5 in high-pollution areas is closely related to PM10, CO, and NO2, SO2 all have a significant positive correlation, and a negative correlation with O3. PM2.5 pollution in Chenzhou City is dominated by local emissions. Transmission path analysis shows that northwest Guangdong, southwestern Henan, Hubei, southern Anhui, and southwestern Jiangxi The local transmission path is the main transmission path of external PM2.5 pollution in Chenzhou City in four seasons; there are obvious seasonal differences in the distribution and contribution of potential source areas. The main contributing source areas in spring, autumn and winter are mainly distributed in southwestern Jiangxi, In northwestern Guangxi and southeastern Hunan, the relatively high value areas in summer are mainly in the form of strips running through the central and western regions of Jiangxi and southeastern Hunan.